• Journal of the Korean Chemical Society
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• v.40 no.12
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• pp.760-762
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• 1996

• BMB Reports
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• v.29 no.2
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• pp.111-115
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• 1996

A novel glutathione S-transferase from Pseudomonas sp. DJ77 was expressed in E. coli and purified by glutathione-affinity chromatography. The enzyme was composed of two identical subunits. The molecular size of the enzyme was 42 kDa by sephadex G-150 gel permeation chromatography and Mr of each subunit was 23 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis. pI value of the enzyme was approximately 5.8 by isoelectric focusing. This enzyme showed the highest activity toward 1-chloro-2,4-dinitrobenzene as the electrophilic substrate. The relative activities toward p-nitrobenzyl chloride and 1,2-dichloro-4-nitrobenzene were 3.8% and 1.3% of the activity toward 1-chloro-2,4-dinitrobenzene, respectively. $K_m$ and $V_{max}$ values for 1-chloro-2,4-dinitrobenzene calculated by Lineweaver-Burk plot were 0.76 mM and $14.81\;{\mu}mol/min/mg$, respectively, and those for glutathione were 6.23 mM and $64.93\;{\mu}mol/min/mg$, respectively. The enzyme showed highest glutathione S-transferase activity at pH 8.0 and was stable between pH 6.0 and 9.0. The enzyme retained its activity up to $35^{\circ}C$ for 90 min but was unstable above $45^{\circ}C$.

• Food Science of Animal Resources
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• v.31 no.3
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• pp.420-427
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• 2011

The use of lactic-acid bacteria (LAB) is effective for preventing and curing immune disorders by activating the immune system in the digestive tract and the consequent immune response in the blood. In this study, LAB and mixed LABs were used in an atopic dermatitis (AD) mouse model. Alleviation of AD was observed based on the change in cytokine level and immunohistochemical staining. An ex vivo test showed that immunoglobulin-E and interleukin (IL)-4 levels were significantly lower in all groups treated with LAB than in the group treated with only 1-chloro-2,4-dinitrobenzene. Results of an in vivo test based on the ex vivo results showed that the scratch score decreased in all groups treated with the LAB and particularly decreased in the group treated with mixed LABs. Additionally, the T helper (Th) 1 cytokines interferon-gamma and IL-12p40 were upregulated by the LAB and mixed-LABs, whereas levels of the Th2 cytokine IL-4 were downregulated in a mouse model of AD-like skin lesions. Furthermore, hematoxylin & eosin and immunohistochemical staining of the dorsal area of the mice in each group showed that AD improved in the LAB-treated groups. These results suggest that LAB and mixed LABs inhibit the development of AD in NC/Nga mice by suppressing the Th2 cell response and increasing the Th1 cell response. Our results indicate that mixed LABs are better than LAB for treating AD-like skin lesions.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.112-112
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.112-112
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• 2005

• BMB Reports
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• v.38 no.2
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• pp.232-237
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• 2005

A glutathione S-transferase (GST) from Lactuca sativa was purified to electrophoretic homogeneity approximately 403-fold with a 9.6% activity yield by DEAE-Sephacel and glutathione (GSH)-Sepharose column chromatography. The molecular weight of the enzyme was determined to be approximately 23,000 by SDS-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. The activity of the enzyme was significantly inhibited by S-hexylGSH and S-(2,4-dinitrophenyl) glutathione. The enzyme displayed activity towards 1-chloro-2,4-dinitrobenzene, a general GST substrate and high activities towards ethacrynic acid. It also exhibited glutathione peroxidase activity toward cumene hydroperoxide.

• Toxicological Research
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• v.7 no.2
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• pp.191-208
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• 1991

Pulmonary conjugation pathways may be important for the metabolism of xenobiotics introduced via airways of systemically. The objective of this study was to determine the pulmonary conjugating capacity in both the isolated perfused rabbit lung (IPRL) and in vitro, and the ability of ethanol to alter the above. The IPRL was capable of conjugating glutathione (GSH) with either 1-chloro-2,4-dinitrobenzene (CDNB) of 1,2-epoxy-(p-nitrophenoxy) propane(ENP). The pulmonary GSH conjugation with ENP was inhibited by cibacron blue, indicating the presence of glutathione-S-transferase (GST) u and/or classes, but it was not altered by buthionine sulfoximine, a selective inhibitor of Gamma-glutamylcysteine synthetase.

• Journal of Life Science
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• v.24 no.8
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• pp.851-859
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• 2014

The present study was designed to investigate whether ethanol extracts of Sophora flavescens (GS), Glycyrrhiza uralensis (GC), Dictamnus dasycarpus (BSP), and their mixtures (GGB-1, -2, -3, and -4) inhibit 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in a mouse model. DNCB was topically applied on the dorsal surface of Balb/c mice to induce AD-like skin lesions. The pathological phenotypes of AD, such as erythema, ear thickness, edema, scabs, and discharge, were significantly decreased in the GGB (DNCB + GS:GC:BSP = 3:1:1 mixture)-1-treated groups compared with the other treated groups. The weight of the spleen in immune organs was significantly decreased in the GGB-1-treated groups, whereas the weight of the liver in a control group was similar to that of the groups treated with the samples. Furthermore, toluidine blue staining analysis, a method used to specifically identify mast cells, showed that master cell infiltration into the dermis of the GGB-1-treated group was significantly decreased. The immunoglobulin E concentration was lower in the GGB-1-treated group. In addition, the levels of inflammatory cytokines (interferon-${\gamma}$, interleukin-1, 4, 5, 6, and 13, $1{\beta}$, and tumor necrosis factor-${\alpha}$) were also significantly reduced in the GGB-1-treated group. Taken together, these results suggest that a mixture of GS, GC, and BSP in a proportion of 3:1:1 (GGB-1) may contribute to the relief of AD symptoms and may be considered an excellent candidate for an AD therapeutic drug.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.374-378
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• 1997

Glutathione S-transferase (GST) was purified from Pseudomonas sp. DJ77, and its N-terminal sequence was determined to be MKLFISPGACSL. A specific tyrosyl residue in the vicinity of the N terminus is conserved in all the known cytosolic GSTs and has been shown to function as a catalytic residue in $\alpha$, $\mu$, $\pi$ class GSTs from mammals. However, Pseudomonas sp. DJ77 GST has the Phe-4 and Ile-5 instead of Tyr in N-terminus. Its replacement with tyrosine did not significantly affect the enzyme activity. Results from in vitro biochemical analyses were confirmed by the in vivo activity-based CDNB growth inhibition analyses. Our results clearly indicate that GST of Pseudomonas sp. DJ77 has a novel reaction mechanism different from that of mammalian GSTs.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2438-2442
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• 2014

A kinetic study is reported for $S_NAr$ reaction of 1-fluoro-2,4-dinitrobenzene (5a) and 1-chloro-2,4-dinitrobenzene (5b) with alkali-metal ethoxides (EtOM, M = Li, Na, K and 18-crown-6-ether complexed K) in anhydrous ethanol. The second-order rate constant increases in the order $k_{EtOLi}$ < $k_{EtO^-}$ < $k_{EtONa}$ < $k_{EtOK}$ < $k_{EtOK/18C6}$ for the reaction of 5a and $k_{EtOLi}$ < $k_{EtONa}$ < $k_{EtO^-$ < $k_{EtOK}$ < $k_{EtOK/18C6}$ for that of 5b. This indicates that $M^+$ ion behaves as a catalyst or an inhibitor depending on the size of $M^+$ ion and the nature of the leaving group ($F^-$ vs. $Cl^-$). Substrate 5a is more reactive than 5b, although the $F^-$ in 5a is ca. $10pK_a$ units more basic than the $Cl^-$ in 5b, indicating that the reaction proceeds through a Meisenheimer complex in which expulsion of the leaving group occurs after the rate-determining step (RDS). $M^+$ ion would catalyze the reaction by increasing either the nucleofugality of the leaving group through a four-membered cyclic transition state or the electrophilicity of the reaction center through a ${\pi}$-complex. However, the enhanced nucleofugality would be ineffective for the current reaction, since expulsion of the leaving group occurs after the RDS. Thus, it has been concluded that $M^+$ ion catalyzes the reaction by increasing the electrophilicity of the reaction center through a ${\pi}$-complex between $M^+$ ion and the ${\pi}$-electrons in the benzene ring.